1. Announcements Quiz tomorrow (obj. 1-5)
Videos due at midnight (no late credit)

2. Restless Electrons
Transfer of Charge

4. Conductive Properties of Materials
NbTi
alloy
metals
silicon
wood
rubber
sea water
pure water
HIGH CONDUCTIVITY LOW CONDUCTIVITY
LOW RESISTIVITY HIGH RESISTIVITY
Good Conductor/
Poor Insulator
Allows electrons to flow freely.
Good Insulator/
Poor Conductor
Strongly resists flow of electrons.

5. RULE #1 – ONLY ELECTRONS MOVE
Charging by Friction
Rub two insulators together
ELECTRONS move from one to the other
One object becomes + the other -
RULE #1 – ONLY ELECTRONS MOVE

6. RULE #2 – GROUNDING MAKES AN
Since the Earth is very large it can neutralize:
negative objects by ABSORBING electrons
positive objects by RELEASING electrons - + - + - - + - +
RULE #2 – GROUNDING MAKES AN
OBJECT NEUTRAL - - -
Grounding Symbol: -

7. Induction – Negative Rod
Induction – movement
of charge without
contact -
RULE #3 – ELECTRONS FLOW TOWARD
LESS NEGATIVE/MORE POSTIVE AREAS - - + - - - - - - - - - - - - - - 3
+ -
- + 1
+ -
- + 2
+ -
ANIMATE
NEXT

8. Induction – Positive Rod
Induction – movement
of charge without
contact - -
RULE #4 – INDUCTION = POLARIZATION - - + - - - - - - - - - - - 1
+ -
- + 2
- + 3 - -
ANIMATE
NEXT

9. Conduction – Negative Rod
Conduction – movement
of charge with
contact
RULE #5 – CHARGING BY CONDUCTION GIVES SAME CHARGE - - - - - - - - - 2 - e- 3 - 1
+ -
- +
ANIMATE
NEXT

10. Conduction – Positive Rod
Conduction – movement
of charge with
contact - - -
RULE #5 – CHARGING BY CONDUCTION GIVES SAME CHARGE + - - 1
+ -
- + 2 + e- 3 + - - -
ANIMATE
NEXT

11. The Electroscope
UNCHARGED
CHARGED - -
LEAVES

12. Induction – Negative Rod - + e- e- 2 + - e- 3 1 - -
RULE #4
ANIMATE
NEXT

13. Induction – Positive Rod - - e- e- 1 2 - + e- 3 + +
RULE #4
ANIMATE
NEXT

14. Charging by Conduction – Negative Rod e- - e- - 2 - e- 4 e- 3 - 1 5 - -
RULE #5
ANIMATE
NEXT

15. Charging by Conduction – Positive Rod e- - e- + 5 3 + 2 - e- + 1 4 e- + +
RULE #5
ANIMATE
NEXT

16. Object A is negatively charged and is used to charge object B by conduction. What is the final charge on objects A and B?
Object A is negatively charged and is brought near neutral object B without touching it. What is the final charge on objects A and B after it is pulled away?
Object A is negatively charged and is used to charge object B by induction. What is the final charge on objects A and B?
A small object is tested to determine its charge. What test could be used to prove that the object is positively charged? What test could be used to prove that the object is not charged?
A negatively charged rod is brought near a neutral electroscope then removed, what is the reaction of the electroscope leaves?
A negatively charged rod is brought near a charged electroscope causing its leaves to diverge. What is the charge on the electroscope?

17. Object A is negatively charged and is used to charge object B by conduction. What is the final charge on objects A and B?
[A -; B -]
Object A is negatively charged and is brought near neutral object B without touching it. What is the final charge on objects A and B after it is pulled away?
[A -; B=0]
Object A is negatively charged and is used to charge object B by induction. What is the final charge on objects A and B?
[A -; B +/- (polarized)]
A small object is tested to determine its charge. What test could be used to prove that the object is positively charged? What test could be used to prove that the object is not charged?
[repelled from + or attracted to -; attracted to + AND -]
A negatively charged rod is brought near a neutral electroscope then removed, what is the reaction of the electroscope leaves?
[diverge (separate) then converge (combine)]
A negatively charged rod is brought near a charged electroscope causing its leaves to diverge. What is the charge on the electroscope?
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